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Automatic Samplers (also called autosamplers or simply samplers) collect and store water samples for laboratory analysis without the need for operator intervention. When used in conjunction with a flume or weir, automatic samplers can collect samples that are truly representative…

While weirs can be useful in a measuring flow in surface water applications, there are distinct disadvantages to using them. For a weir to develop the necessary upstream velocity profile, the channel upstream of the weir must conform to certain specific requirements:

Galvanized steel is commonly used for flumes and (somewhat less so) weirs in irrigation and water rights applications. Galvanized steel is economical and can provide a good useful lifespan.

At its simplest, a weir box is a fabricated channel into which a weir plate has been installed.

A Packaged Metering Manhole (PMM) is a factory-integrated fiberglass manhole that mounts a flume, weir, mag meter, or other primary device to allow a user to measure or sample flows from full or non-full pipes. The manhole tube can also be supplied with a range of accessories,…

A flow measuring weir is simply a structure over which water flows in such a way that volumetric flow rate can be calculated….it lets you know how much water is flowing. Many times a flow measuring weir is simply a thin plate across a flow stream, but weirs can also be broad,…

Weirs are often described as “simple” and “low cost” ways of measuring open channel flows and, made of some materials they really are low cost. But this low cost comes at a price. Steel plate is frequently used to keep costs down and, when it is new, it’s a perfectly…

Weirs, like flumes, work by accelerating slow, sub-critical flow (Fr1). The acceleration develops a know relationship between level and flow upstream of the weir itself. But what happens when the flow approaching the weir isn’t sub-critical, but instead is critical or…

Measuring open channel (non-full pipe) flows in round pipes can be difficult when measurement costs need to be low or where power is not available at the site. There are proprietary weir inserts available, but they can be inconveniently sizes or insensitive or unrated for the…

YouTube user Pener Pã has posted an interesting video showing the installation of a Rectangular Weir Plate with End Contractions into a natural channel.

Pressure transducers are a popular method of measuring the water level in flume or weir installations. They are used by water resource managers, engineers, and hydrologists to monitor flow rates in a range of applications, including: agriculture (runoff and water use), watersheds…

With the adoption of SB 88 by the California State Water Board all smaller water users are now required to monitor and report the usage. This can be daunting. But take hope…all is not lost! At the center of any compliance program is the flow meter. For non-pumped sources, a…